God is the great “I Am”. You can’t reduce God to an instance in time–you can’t reduce God to a snapshot.
Grace like God–FLOWS.
It has a starting point–conversion but it flows on from there.
It doesn’t always necessarily keep flowing.
It ends for any of us if we mortally sin. If we don’t mortally sin it keeps flowing through “God willed works” until we die. That is salvation and we wind up in Heaven.
When grace is interrupted and stops flowing because of mortal sin–if the flow isn’t restarted then at death we go to Hell.
“God willed works” ARE a part of God’s flowing grace.
Man willed works apart from God’s will happen when the flow of God’s will is stopped during mortal sin. They do not save because they are not part of the flow of actual grace.
Doing or not doing any kind of work saves us when we are in the flow of God’s grace and do His willed works. Doing a work does not save us if we are outside of the flow of God’s grace and are doing something that we will–no matter how noble that work might be it doesn’t save–NOT because of the value of the work–but because it is outside of the flow of God’s grace–it is not something that He wills.
When we know to do something and do it–it is not our doing the work that saves us–it is NOT resisting what God wants done–in other words by doing a work that He wants we do not interrupt the flow.
In a case like that the fact that we do what God wills is because of His grace–not our effort.
So God does ALL of the saving–but God gives us free will and lets us CO–OPERATE in His saving of us. It is a divine mystery but it is true.
It is not though true that God’s grace always necessarily continues after it first starts in us–at any time we can interrupt that grace through mortal sin. If the flow is stopped at our death then we go to Hell!
The easy truth that Protestants try to push is that God’s saving flow never stops once started and always necessarily results in salvation… that is false.
And mortal sin is a fact–God does not keep living in the sinful heart of man once one mortally sins.
Staying in a state of grace leads to heaven and only happens when we don’t stop God’s saving grace in us which during our lives does continue time to time through works that HE WILLS!
The reason we “work out our salvation with fear and trembling” as St. Paul tells us to do is that all of us should fear Hell and fear that we might not be in a state of grace when we die and wind up going there–none of us wants that–but God gives us grace through the sacraments for that not to happen.
Not being afraid of being in a state of mortal sin as the Protestants teach and not believing that mortal sin does in fact separate us from God WILL result in Hell if we die in that state.
So see it is not anything that we do that earns us heaven–it is us not stopping His grace in us–which sometimes involves doing what He wills and staying in that state which saves us–He does ALL the saving–we cooperate by not getting in God’s way!
That cooperation happens because of God’s grace AND the operation of our free will.
How can it be both? That is a mystery but it is the truth!